<template lang="html">
  <div class="star" :class="starType">
    <span v-for="itemClass in itemClasses" :class="itemClass" class="star-item"></span>
  </div>
</template>

<script>
const LENGTH = 5;
const CLS_ON = 'on';
const CLS_HALF = 'half';
const CLS_OFF = 'off';

export default {
  props:{
    size:{
      type: Number
    },
    score:{
      type: Number
    }
  },
  computed:{
    starType() {
      return 'star-'+this.size;
    },
    itemClasses() {
      let result = [];
      let score = Math.floor(this.score*2)/2;
      let hasDecimal = score % 1 !==0;
      let integer = Math.floor(score);
      for(let i=0;i<integer;i++){
        result.push(CLS_ON);
      }
      if (hasDecimal) {
        result.push(CLS_HALF);
      }
      while (result.length<LENGTH) {
        result.push(CLS_OFF);
      }
      return result;
    }
  }
}
</script>

<style lang="less">
  .star{
    font-size: 0;
    .star-item{
      display: inline-block;
      background-repeat: no-repeat;
    }
    &.star-48{
      .star-item{
        width: 20px;
        height: 20px;
        margin-right: 22px;
        background-size: 20px 20px;
        &:last-child{
          margin-right: 0;
        }
        &.on{
          background-image: url('star48_on@2x.png');
        }
        &.half{
          background-image: url('star48_half@2x.png');
        }
        &.off{
          background-image: url('star48_off@2x.png');
        }
      }
    }
    &.star-36{
      .star-item{
        width: 15px;
        height: 15px;
        margin-right: 6px;
        background-size: 15px 15px;
        &:last-child{
          margin-right: 0;
        }
        &.on{
          background-image: url('star36_on@2x.png');
        }
        &.half{
          background-image: url('star36_half@2x.png');
        }
        &.off{
          background-image: url('star36_off@2x.png');
        }
      }
    }
    &.star-24{
      .star-item{
        width: 10px;
        height: 10px;
        margin-right: 3px;
        background-size: 10px 10px;
        &:last-child{
          margin-right: 0;
        }
        &.on{
          background-image: url('star24_on@2x.png');
        }
        &.half{
          background-image: url('star24_half@2x.png');
        }
        &.off{
          background-image: url('star24_off@2x.png');
        }
      }
    }

  }
</style>
